Why does my iPhone say connect to itunes?

Ok so my phone was very normal until it died so I charged it. I left it on the charger for about an hour or two as usal, but when i came back my phone said ios 6 on the lock screen and when i swiped it said connect to itunes. When i unplug my phone from the charger it does not work or turn on at all. What do I do?

It was probably updating and now you need to reset it

Kind of sounds like it's stuck in a boot loop. It can happen for many reasons but 99% of the time it's due to water damage.